1. Field of the Invention
The present invention generally relates to a bus bar configuration for an electric machine.
2. Description of Related Art
Electric machines and switch configurations for controlling electrical machines are well developed in the art. Typically, the switching electronics are packaged and mounted separately from the electric machine. With the switching electronics and electric machine typically connected through multiple connectors and a wire harness, it is advantageous to reduce the number of connectors and wire harnesses to improve system reliability and decrease system cost. In addition, the elimination of such connections reduces electrical noise and cross talk between adjacent electrical systems.
Conventionally, a bus bar and switch circuits are laid out linearly on a circuit board in a open loop configuration. The open loop or linear arrangement of the switch circuits causes the distance between each switching circuit and capacitor to vary. Therefore, filtering and snubbing capacitance is not equally shared among the switch circuits, due to the asymmetric layout of the circuit board. The unequal sharing of such capacitance may cause slight timing delays between the switch circuits, exposing certain switches to an unequal amount of current thereby overloading the switch during the delay and causing potential reliability issues.
In view of the above, it is apparent that there exists a need for an improved bus bar configuration for an electric machine.